A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Sannibale, F.

Paper Title Page
TUOCAB02 Measurements of Compression and Emittance Growth after the First LCLS Bunch Compressor Chicane 807
 
  • P. Emma, K. L.F. Bane, Y. T. Ding, J. C. Frisch, Z. Huang, H. Loos, G. V. Stupakov, J. Wu
    SLAC, Menlo Park, California
  • E. Prat
    DESY, Hamburg
  • F. Sannibale, K. G. Sonnad, M. S. Zolotorev
    LBNL, Berkeley, California
 
  Funding: U. S. Depertment of Energy contract #DE-AC02-76SF00515.

The Linac Coherent Light Source (LCLS) is a SASE x-ray free-electron laser project presently under construction at SLAC. The injector section from RF photocathode gun through the first bunch compressor chicane was installed during the Fall of 2006. The first bunch compressor chicane is located at 250 MeV and nominally compresses a 1-nC electron bunch from an rms length of about 1 mm to 0.2 mm. The degree of compression is highly adjustable using RF phasing and also chicane magnetic field variations. Transverse phase space and bunch length diagnostics are located immediately after the chicane. We present measurements and simulations of the longitudinal and transverse phase space after the chicane in various beam conditions, including extreme compression where coherent radiation effects are expected to be striking.

 
slides icon Slides  
TUPMN112 ALS Top-off Simulation Studies for Radiation Safety 1173
 
  • H. Nishimura, R. J. Donahue, R. M. Duarte, D. Robin, F. Sannibale, C. Steier, W. Wan
    LBNL, Berkeley, California
 
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC03-76SF00098

We plan to commission top-off injection at the Advanced Light Source in the near future. In order to guarantee radiation safety, we have been simulating the injection process to exclude the possibility of injected electrons traveling down the user's photon beam lines. As the final stage of our simulation study, we use photon beam line CAD drawings to define the beam line's aperture in the phase space which electrons must not enter. Then we virtually inject electrons from within these phase spaces backwards into the storage ring to prove that such electrons can never get back to the real injection point under any possible scenario. This paper summarizes such inverse tracking studies.

 
THOBC02 Absolute Bunch Length Measurements at the ALS by Incoherent Synchrotron Radiation Fluctuation Analysis 2661
 
  • F. Sannibale, M. S. Zolotorev
    LBNL, Berkeley, California
  • D. Filippetto
    INFN/LNF, Frascati (Roma)
  • G. V. Stupakov
    SLAC, Menlo Park, California
 
  Funding: This work is supported by the Director, Office of Science, High Energy Physics, U. S. Dept. of Energy under Contract no. DE-AC02-05CH1121

By analysing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.

 
slides icon Slides  
THPMN117 Design of a VHF-band RF Photoinjector with MegaHertz Beam Repetition Rate 2990
 
  • J. W. Staples, K. M. Baptiste, J. N. Corlett, S. Kwiatkowski, S. M. Lidia, J. Qiang, F. Sannibale, K. G. Sonnad, S. P. Virostek, R. P. Wells
    LBNL, Berkeley, California
 
  Funding: This work is supported by the Director, Office of Science, High Energy Physics, U. S. Dept. of Energy under Contract no. DE-AC02-05CH1121

New generation accelerator-based X-ray light sources require high quality beams with high average brightness. Normal conducting L- and S-band photoinjectors are limited in repetition rate and D-C (photo)injectors are limited in field strength at the cathode. We propose a low frequency normal-conducting cavity, operating at 50 to 100 MHz CW, to provide beam bunches at a rate of one MegaHertz or more. The photoinjector uses a re-entrant cavity structure, requiring less than 100 kW CW, with a peak wall power density less than 10 W/cm2. The cavity will support a vacuum down to 10 picoTorr, with a load-lock mechanism for easy replacement of photocathodes. The photocathode can be embedded in a magnetic field to provide correlations useful for flat beam generation. Beam dynamics simulations indicate that normalized emittances on the order of 1 mm-mrad are possible with gap voltage of 750 kV, with fields up to 20 MV/m at the photocathode, for 1 nanocoulomb charge per bunch after acceleration and emittance compensation. Long-bunch operation (10's of picosecond) is made possible by the low cavity frequency, permitting low bunch current at the 750 kV gap voltage.

 
TUPMN109 A High Repetition Rate VUV-Soft X-Ray FEL Concept 1167
 
  • J. N. Corlett, J. M. Byrd, W. M. Fawley, M. Gullans, D. Li, S. M. Lidia, H. A. Padmore, G. Penn, I. V. Pogorelov, J. Qiang, D. Robin, F. Sannibale, J. W. Staples, C. Steier, M. Venturini, S. P. Virostek, W. Wan, R. P. Wells, R. B. Wilcox, J. S. Wurtele, A. Zholents
    LBNL, Berkeley, California
 
  Funding: This work was supported by the Director, Office of Science, High Energy Physics, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The FEL process increases radiation flux by several orders of magnitude above existing incoherent sources, and offers the additional enhancements attainable by optical manipulations of the electron beam: control of the temporal duration and bandwidth of the coherent output, and wavelength; utilization of harmonics to attain shorter wavelengths; and precise synchronization of the x-ray pulse with laser systems. We describe an FEL facility concept based on a high repetition rate RF photocathode gun, that would allow simultaneous operation of multiple independent FELs, each producing high average brightness, tunable over the soft x-ray-VUV range, and each with individual performance characteristics determined by the configuration of the FEL SASE, enhanced-SASE (ESASE), seeded, self-seeded, harmonic generation, and other configurations making use of optical manipulations of the electron beam may be employed, providing a wide range of photon beam properties to meet varied user demands. FELs would be tailored to specific experimental needs, including production of ultrafast pulses even into the attosecond domain, and high temporal coherence (i.e. high resolving power) beams.

 
TUPMS003 Status of the Top-off Upgrade of the ALS 1197
 
  • C. Steier, B. J. Bailey, K. M. Baptiste, W. Barry, A. Biocca, W. E. Byrne, M. J. Chin, R. J. Donahue, R. M. Duarte, M. P. Fahmie, J. Gath, S. R. Jacobson, J. Julian, J.-Y. Jung, S. Kwiatkowski, S. Marks, R. S. Mueller, H. Nishimura, J. W. ONeill, S. Prestemon, D. Robin, S. L. Rossi, F. Sannibale, T. Scarvie, D. Schlueter, D. Shuman, G. D. Stover, CA. Timossi, T. Warwick, J. M. Weber, E. C. Williams
    LBNL, Berkeley, California
 
  Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The Advanced Light Source is currently being upgraded for top-off operation. This major facility upgrade will provide an improvement in brightness from soft x-ray undulators of about one order of magnitude and keep the ALS competitive with the newest intermediate energy light sources. Major components of the upgrade include making the booster synchrotron capable of full energy operation, radiation safety studies, improvements to interlocks and collimation systems, diagnostics upgrades as well as emittance improvements in the main storage ring. The project status will be discussed as well as results of major parts of the commissioning.

 
FRPMN003 Measurements of Impedance and Beam Instabilities at the Australian Synchrotron 3859
 
  • R. T. Dowd, M. J. Boland, G. LeBlanc, M. J. Spencer, Y. E. Tan
    ASP, Clayton, Victoria
  • J. M. Byrd, F. Sannibale
    LBNL, Berkeley, California
 
  In this paper we present the first measurements of machine impedance and observed beam instabilities at the Australian Synchrotron. Impedance measurements are made by studying the single bunch behaviour with beam current, using optical and X-ray diagnostic beamlines. An observed coupled-bunch instability, its cause and cure is also discussed.